VATREG19100 - Exception from registration: the law
The primary legislation governing exception is contained in the VAT Act 1994, Schedule 1, paragraph 1(3).
(3) A person does not become liable to be registered by virtue of sub-paragraph (1)(a) or (2)(a) above if the Commissioners are satisfied that the value of his taxable supplies in the period of one year beginning at the time at which, apart from this sub-paragraph, he would become liable to be registered will not exceed [the current deregistration limit].